APA (7th ed.) Citation

Collingwood, G. H., Brush, W. D., & Butcher, D. (1974). Knowing your trees. American Forestry Association.

Chicago Style (17th ed.) Citation

Collingwood, G. H., Warren David Brush, and Devereux Butcher. Knowing Your Trees. Washington: American Forestry Association, 1974.

MLA (9th ed.) Citation

Collingwood, G. H., et al. Knowing Your Trees. American Forestry Association, 1974.